The present invention relates to a heat exchanger and a condensation combustion chamber assembly for the passage of the fumes generated by air/gas combustion, produced by a pre-mixed burners coupled to the combustion chamber.
Such an assembly, as is known, has a very high efficiency, of the order of 105% and generates, as combustion products, in addition to the combustion fumes, also water steam, which is conveyed to the outside environment, through a dedicated conveying duct.
In such an embodiment, it is necessary to increase or enhance the thermal exchange between the fumes and secondary air to be heated, while preventing any generations of laminar flows with thermal gradients inside the exchanging tube, which would cause a decrease of the thermal exchange with the secondary fluid.
A further problem is that of the high heating of the combustion chamber, operating in cooperation with premixed gas burners having a very high unit power for flame surface.
The first problem, related to the increase of the thermal exchange in the heat exchanger tubes, has been solved by providing “turbulating” devices, inside said heat exchanger tubes.
The above mentioned devices, made of stainless steel and having a rectangular cross-section blade configuration, deformed in the form of a spiral helix, were designed for generating a turbulent motion in the hot fume path, to prevent any laminar effect from occurring, with a consequent decreasing of the heat amount being exchanged.